We're close, but we're not that close.

That's what Rita Forst, head of development at General Motors' Opel division, seemed to be saying when discussing the possibility of GM and PSA Peugeot Citroën sharing advanced-powertrain trade secrets.

Speaking at an automotive industry conference in Munich last week, Horst said she "can't imagine" GM giving Peugeot tips on its Chevrolet Volt extended-range plug-in in exchange for Peugeot's disclosures about its 3008 Hybrid4 diesel hybrid, Reuters reports.

In February, GM agreed to acquire 7 percent of PSA in a collaboration that would allow the U.S. and French automakers to share midsize vehicle and crossover platforms and cut costs by combining component purchases. GM estimated that the alliance would eventually save the company $2 billion a year.

Last month, Opel said its Ampera, the Volt's sister vehicle, accounted for more than 20 percent of all electric vehicle sales in Europe, making it the best-selling EV on the continent. In March, the Ampera (and Volt) won the 2012 European Car of the Year award.